I would say that if you have a big tank, then its useful. But to be honest, I have used mine twice since I bought it and I must not have the water pressure necessary to make the vacuum clean the gravel very well. it doesn't do as good a job as the regular vacuum siphon. Hooking it up and working with it, for me, seemed to be no more work and hassle than using the buckets. Yes, the mess is much less, but thats why I have towels. Missleman's points are all great and I agree with them, though personally, I continue using the buckets on my 40gallon instead of the python because its just simpler to start vacuuming, dumping and refilling as opposed to unraveling 25' of hose, unscrewing the sink adaptors and attaching the python's, hooking it up, starting the vacuuming, quickly switching from vacuuming to refilling, then unhooking all of it and rolling up the hose. So, for me, I just use my trusty siphon vacuum and a bucket.